In the past, there have been dehumidifying apparatuses combining a heat pump and desiccant that adsorbs and desorbs moisture. As one of such dehumidifying apparatuses, a dehumidifying apparatus has been proposed in which an air passage is divided to allow airflows having different relative humidity values to pass through a rotor-shaped desiccant material, which is rotated to repeat adsorption reaction and desorption reaction (see Patent Literature 1, for example). Further, at a low temperature (10 degrees Celsius, for example), the dehumidifying apparatus described in Patent Literature 1 allows air heated with a heater to flow into the desiccant material to facilitate the release of moisture. This configuration increases the humidity and the amount of humidification, and the heated air passes through an evaporator, thereby increasing the evaporating temperature and suppressing frost formation on a heat exchanger.